Polymer based materials capable of forming amorphous thin films have been used so far as typical resist materials. For example, a line pattern of about 45 to 100 nm is formed by irradiating a resist thin film made by coating a substrate with a solution of a polymer resist material such as polymethyl methacrylate, polyhydroxy styrene with an acid dissociation reactive group, or polyalkyl methacrylate with ultraviolet, far ultraviolet, electron beam, extreme ultraviolet (EUV), and X-ray or the like.
However, because polymer based resists have a molecular weight as large as about 10,000 to 100,000 and also wide molecular weight distribution, in lithography using a polymer based resist, roughness occurs on a fine pattern surface; the pattern dimension becomes difficult to be controlled; and so the yield decreases. Therefore, there is a limitation in miniaturization with lithography using a conventional polymer based resist material. In order to make a finer pattern, various low molecular weight resist materials have been proposed so far.
For example, an alkaline development type negative type radiation-sensitive composition (see Patent Documents 1 and 2) using a low molecular weight polynuclear polyphenolic compound as a main component has been suggested.
Also, as a low molecular weight resist material having high heat resistance, an alkaline development type negative type radiation-sensitive composition (see Patent Document 3 and Non Patent Document 1) using a low molecular weight cyclic polyphenolic compound as a main component has been suggested.